8V non start plus serious error icon

Any experience of this serious error (ECU) message and any ideas on getting rid of it? Or have I got expensive trouble?

1200 8V (Griso)
I don’t need to go into details of the intermittent non-start issue as it’s been much reported: but could it have a connection to the serious error (ECU) warning appearing at bottom of dash display?

Having thwarted my holiday by killing the bike after going less than 100 miles on Friday, I eventually got the bike running again by starting it with a wire to give a direct feed from the battery to the solenoid, bypassing the wiring, fuses, relays – and I took the bike home without stopping it.

Though I have experienced this non-start issue since getting the bike 4 years ago, I have never had fuse or relay problems. This time the starter fuse blew and the spare blew when swapped in. Now, at home today, the dash is displaying the ‘! SERVICE’ warning, which means a serious fault and I think an ECU related problem. The diagnostics code shows an ECU 56 fault, which is a ‘Vehicle Speed Error’, whatever that means. The appearance of this error may be coincidental, or could it be related to the non-start and fuse problem? Any experience, ideas?

I have disconnected power to ECU, but the fault message keeps showing when powered up again. Apart from connecting to Axone or any other mythical diagnostic device, what can I do about this error? I have spent all day stripping, checking all sorts of things. Bike is now starting and not blowing fuse, but the serious error display persists.

Of course the non-start could happen ageing any time and perhaps the fuse blowing could happen again. It seems from others’ experience that once this starter fuse starts blowing, it keeps happening on a fairly regular basis. I will modify the wiring with a direct feed from battery to relay (yellow wire): but this new error message is worrying.

This info may or may not be relevant:–
The semi-working neutral light problem led to this latest incident. The neutral indicator only works half the time. It’s always been like this but dealers and Piaggio UK have always refused to fix it (warranty) or give advice. When I stopped at toll booth on motorway to Dublin, I tried to find neutral as I often have to – without the aid of a green indicator. Unfortunately it caught a gear, lurched and stalled. It was after this lurch/stall that the bike no longer started (and perhaps the fuse blew then, but I don’t know).
(I’ll ask about the neutral switch in a new thread.)
belfastguzzi2012-07-29 01:26:37

No idea what ECU56 is about or whether it has any bearing on the non start issue. But the fact that you have blown 2x15A fuses would suggest one of the things mentioned in the Click, no Crank thread in FAQ, the later discovery I made with the sticky dry grease in the solenoid housing being the most likely, but if you haven’t done the wiring mod, you should.

Have you asked on Guzzitech about the ECU error code?

‘Vehicle speed error’ suggests to me vehicle speed sensor fault, naturally the ECU would like to know how fast it’s going

Wherever it is, possibly clagged up with crud or bad electrical connection, wasn’t there somebody has theirs on the front wheel hub? OK after a clean up?

The starter motor current wouldn’t go through the fuses of course, so can only imagine a wiring short somewhere, in the area of the starter relay wiring.

I don’t supoose you could direct us to the wiring mod link? Thanks

Brian, how did you get the yellow wire spade terminal out of the relay connector block without damaging the plastic?
I think that is what you did, rather than cut the yellow wire itself.

I’m not having any success removing it.

As always, the whole thing is a mystery. I have been over all the wiring and connectors and can’t find a problem. Also no matter what I isolate, the dash still shows that serious error alert that obliterates the usual readout at the bottom of the display. I fear that it may be a problem with the ECU itself. Once I get the bike together again I will run it on the road to see if anything is obviously amiss. The engine is starting now and is not blowing fuses. This is great but it is also the curse of intermittent problems. Why does it sometimes work and sometimes not?

I don’t believe that there is any problem with the speed sensor. I think that the ECU code 56 (Vehicle Speed) is logged from some previous incident. Sensor wiring and continuity is ok, plus the display was showing the speed perfectly. I think that these error logs do not clear. Perhaps the official diagnostics equipment (Axone/Navigator) is needed to clear the ECU error log.

I also don’t think that the starter itself contributed to the problem. I do keep it clean and free. However I have again disassembled it to clean and lube the starter shaft and the solenoid plunger. It is undoubtedly freer after doing so.

As well as a direct feed from the battery to the relay, I am adding an additional ground connection on the frame. If I could figure out what Todd’s original post on Guzzitech is talking about exactly, I may also back up the start switch wire with a direct parallel cable – I think that is what he is saying? I can’t see that is really necessary though.

I have found Carl Allison’s re-drawing of the wiring diagram to be immensely helpful, however the wire colours do not always match my bike. Have you found that with yours?

Anyway, can the spade be removed or should I cut the plastic connector?

BTW, are the 4-pin relays easily available? Halfords don’t have them and Hein Gericke looked at me as if I had two heads when I showed it. Other motor places were closed on Saturday afternoon when I was looking.
belfastguzzi2012-07-30 01:13:15

The serious error (ECU) warning that is permanently displayed.

I’m now wondering if this may not necessarily mean that there is still a fault: perhaps this message can only be cleared via the official service diagnostics equipment (Axone, Navigator)?


Don’t know how easy / difficult this would be, but do you know anyone localish who would be willing to let you put their ECU into your bike for a few minutes?


Hi Andrew, no: there’s no other Griso that I can access – but I wouldn’t like to ask anyway… just in case the other ECU got damaged in some way.

At the moment, my hope is that there isn’t anything seriously wrong and that when I get the bike back together and ride it, the Service (ECU error) will eventually clear. I have also learnt of diagnostics software that can be downloaded: Ducatidiag. Anyone used it? I guess it works on Windows, which adds an extra level of complexity as I’m on Mac, plus I’d need the correct adaptor lead. I’m also thinking that some independent bike shop will have universal diagnostics equipment that will interface with the modern Guzzis.



Might be of help

Usually a speed sensor problem comes up as a dashboard error.

To get the spade out of the socket, push a small jeweller’s screwdriver down the wire end of the holder to release the little tab.

Those 4 pin relays seem to be peculiar to the Piaggio group, haven’t found them anywhere else.

Ah yeah, I was trying to think what I had that would be fine enough, but didn’t think of the jeweller blade. I just cut the plastic. It doesn’t make much odds once the connector is back in the relay holder.

Anyway, I have interesting findings and I trust that the problems (apart from the neutral sensor) are fixed – so far so good, but I’ll need some time/miles to be sure. Vehicle Speed is what the MG Griso Service Manual gives for the 56 code. However I’ve found that it wasn’t speed/speed sensor.

I’ll report back later with details/findings. Thanks for help.belfastguzzi2012-07-31 11:53:58

Mike I don’t know where you get the idea that I was suggesting that the motor current went through the relay, indeed it is made clear that the motor wasn’t turning.
The solenoid has two coils in it, a heavy one to pull it in and a lighter holding one once it has made the contacts. The former takes between 25 & 30 Amps, and so if for any reason the solenoid doesn’t pull in completely, the 15A fuse will blow very quickly. Low voltage supplied to the solenoid terminal is one of the main culprits as researched by many, the rewire cures this.

Take a look see here at the high current 4 pin relays

Non of those fit Ken.

Then in that case I would rewire a base and get a 30A relay that fits, Guzzi must have got a job lot cheap …lol

This is very interesting, I will have to go out and measure mine. When it stops raining!

OK I did the magic measuring thing on me solenoid.

Well well well well!

I make it 0.3 Ohms

It must therefore rely on inductive reactance to keep things more civilised, otherwise it could be 30 - 40 Amps.

Mike, if you’re interested in the measurements, here are some figures given by someone in a different discussion that I’m having about this. This is on a 2001 bike.


"If you measure the current drawn by the solenoid with a multimeter it shows less than 10 Amps which shouldn’t be a problem but this is just the holding current, the real work the solenoid does is in the fraction of a second between the time the start relay closes and when the solenoid closes it’s main contact, it takes a massive magnetic field to engage the starter gear

A Valeo will pull about 50 Amps, a Bosch about 40
If you calculate the resistance of the two coils in parallel it works out ~ 0.2 Ohms

Say for argument sake you had a total resistance of 0.2 Ohms through all the wiring, ignition switch, fuse, relay the instant current would be 12 / (0.2 + 0.2) = 30 Amps

By cutting out half the wiring it’s reasonable to think you could at least cut the resistance in half e.g. 0.1

So now the current to pull in the starter is 12 / (0.1 + 0.2) = 40 Amps
BTW I think I am being realy generious in saying the total wiring is only 0.2 Ohms, I have seen the ignition switch alone many times that.

I honestly don’t think Guzzi understand there are two coils in the starter solenoid otherwise they might show it in their schematics.

30 Amps 0.2 Ohms = 180 Watts - This is the power available for the solenoid to do it’s work, the power dissipated in the wiring is lost.
With a better circuit
40 Amps 0.2 Ohms = 320 Watts - Almost double the power"belfastguzzi2012-08-02 19:02:10

It’s not so much the resistance in the wiring, more that this current is taken through the ignition switch contacts which are not rated for that sort of current.
Been the same since Guzzi invented the V Twin though, they don’t learn.